Single-phase alternating-current motor with commutating-poles.



No. 353.491. PATENTED MAY 14, 19-07.

' E. ARNOLD & J. L. LA GOUR.

SINGLE PHASE ALTBRNATING CURRENT MOTOR WITH GOMMUTATING POI-ES. APPLICATION FILED 001 .9. 1905.

a UNITED; STATES E E OFFICE.

"ENGELB'ERT ARNOLD, OF-KARLSRUHE, GERMANY, AND JENS LASSEN LA COUR,.OF EDINBURGH, SCOTLAND.

SINGLE-PHASE ALTERNATlN G-CURRENT MOTOR WITH COMMUTATING-POLES To (ZZZ whom it may concern:

-, =1 Be-it known that we, ENGELBERT ARNOLD,

of Karlsruhe, 'Germany,a'nd JENs vLAssEN La COUR, of-Edinburgh, Scotland, have invented-certain new and useful Improvements in Sin le-Phase Alternating Current Motors with ommutating-Poles, of which the followin is a specification.

Inirect current machines for highspeeds v and heavy overloads, .commutatingf poles are-frequently employed toobtain'a sparktation inthe shortcircuited coils.

less' commutation. These poles are excited by the armature current to such a strength that the "fieldbeneath them is oppositely di- 55' rected to the armature field and ust suffices to induce. the E. M. F. necessary for commu- Thesame arrangement. has been several times proposed for single phase motors, but since in single hasemotors the pulsation of. the main-field -1nduce's'larg'e E. M. Fs in the short circuited coils, it is here necessary to excite the comnmtating poles in a different manner to that for -direct current machines.

which not onl tion, but pro uces'a great self-inductive re- ;"actan'ce in the armature.

When cornmutatingj poles are 'used, means have to be provided for preventing'the armature am ere. turns from producing a strong cross fie d through the commut'ating poles,

is harmful to the commuta- "ipensating windings are provided, one part of which is distributed in the pole shoes oflthe main poles, while'the, other part is on'the ,"co'mmutatin'g poles; these compensating windings are connected in series to the arma- {tu're so as to neutralize completely the arma- '-t11re field. On theother hand-a commutating field has to be excited displaced about 90 in phase to the main field, since the E. M. F. induced by the main field in the short circui ted coilsl about 90 behind it. fore the exciting windings of this commutating field are' connected to a voltage in phase 'with the main field as will be shown inthe following:

In the drawing forming-a part of the specification'Fi% ure 1' is apartial side-view of amachine em odying the invention; and Figs. 2- and 3 "are diagrams showing the'various connections described p Fig. 1" shows the arrangement for a' four pole machine W l 'h'themain poles P and .the

co mnutatingfgptiles;13,; is the armature Specification of Letters Patent.

Application filed October 9,1905. Serial No. 282.014..

Therefore com' Therea mately-' 4O% above sync onism the Patented May 14, 1907.

and C a part of the armature windingis. K is correthe commutator with four brushes sponding to the number of poles, the brushes of like polarity being connected to each other as in any multipolar. machine. CW is the compensatin winding lyin in slots in the pole shoes 0 the main po es, and W the windinglon the commutating poles, both carrying t e armature current. The compensation winding of-the main poles is provided with a number of ampere-turns equal to that of the 'ortion of the armature winding lying circuited coils; 5 There is besides the compen-- sati ng windir. gon the main poles also the ex-' citing winding E. W. necessary for the production of themain field and this winding is connected in series to the armaturein .a series motor and in arallelto the armature in a shunt motor: 11 order to compensate the E. M. Fs induced in the short circuited armature coils by the main poles, a second windin W, "is arranged on the commutatin This win po es. ingis shunt excited an reduces under the commutating poles a eld, which is nearly or in time a quarter period, displaced from the main field, since,

when the motor is running its volta e is,-

nearly, in phase with the-main field. I the short circuited armaturecoils rotate in the field ofthe winding-W5 E; M. Fs are induced in them which oppose the E. M.'-Fs induced by the pulsation of the main field." The commutating field should be as strong .as possible. v With regard however to the hysteresis losses produced in the teeth rotating in this field, too strong a commutating-field is not desirable, .But even if the commutating field is made only half as strong as the main field at synchronism, a very favorable action 3 is obtained at higher s eeds. At F s induced in the short circuited coils will in this case vanish. 2 shows diagrammatically the con-" slots in the main nections of the diil'erent windings for a series motor. The exciting winding E. W. of the main poles as well {as the compensating windings (J. W. and the windin l/V of the commutating poles are connectedin series to the armature A. R is the starting resistance. poles is connected to the mains. However, since onepart of the total volta e-corresponding to the E. M. F. of the exciting winding E. W. is in quatrature to the main field it is in many cases advisable to connect the shunt excited winding WV in parallel to the armature. the connnutating field in the short circuited coils are proportional to the square of the speed; therefore it is preferable at starting to connect the winding W in parallel with the armature and starting resistance as is shown inFig. 3 for a seriesmotor. o

In the arrangement described the component parts are already known. The combination and correct proportions of these known elements is, however, new.

\Vhat is claimed. is.

1. A single phase alternating current motor with a compensation winding lying in oles and having the same ampere-turns as the portion of the armature Winding under these poles and with commutating poles carryin two windings one of which in series and the other shunt excited, substantially as described.

2. A single phase alternating current motor with a compensation Winding lying in slots in the mam alnpereaurns as t e portion of the armature The Winding W of the coinmutating' In this case the E. M. Fs induced byv poles and having the same winding under these poles and with commutating poles carryin two windings one of which in series and the other shunt excited, the series excited windings of the commutatturns than the portion of the armature winding between the main poles.

3. A single phase alternating current Inotor with a compensating winding lying in slots in the main oles and having the same ampere-turns a t e portion of thearmature Winding under hes e poles and with comma being connected to the mains. 4. A single phase alternating current mo- ENGELBERT ARNOLD. JENS LASSEN LA coon.

' Witnesses for Engelbert Arnold.-

- H. VV/Hnnnrs,

Jos. H. LEUTE. Witnesses for Jens Lassen la Cour:

ROBERT F. Sco'r'r, GEORGE BRAID.

ing poles having somewhat more ampere tating poles carrying two windings one of which 1n series and the other shunt excitedtor with a starting resistance and withacom 

